Flow within a blood vessel or other body lumen within a patient's vasculature may become constricted or ultimately interrupted for a variety of reasons. For example, a vessel may gradually narrow due to inflammation and/or cell proliferation. In addition, thrombus may form due to such narrowing or other flow problems within a vessel.
One approach to removing unwanted material, e.g., thrombus, that is adherent to a vessel wall may involve advancing a device, e.g., a Fogarty embolectomy balloon, to a point beyond the adherent material blockage, expanding the device to the dimension of the vessel interior, and then withdrawing the expanded device back with the intent to sweep the adherent material out of the vessel. While this approach is frequently successful, there are some instances where the adherent material does not release from the vessel wall and stays within the vessel even after multiple passes.
Another approach to removing the adherent material is to advance a rotating structure that can abrade the surface of the adherent material or become entangled in the adherent material, thereby forcing the adherent material to release from the vessel wall. For example, the Arrow Treratola device has several helical wires that expand radially outward to contact the vessel wall. These wires are spun at a high speed via a driveshaft connected to an electric motor in the hand piece of the device. During operation, the Treratola device rubs against the inside wall of the vessel as it is advanced. Upon engaging adherent material, the device abrades the inside surface of that material, and in many cases, the device may break through the interface between the adherent material and the vessel wall. In this event, the adherent material can be peeled off the vessel wall and become wrapped around the helical wires of the Treratola device.
While this may address the immediate goal of removing the adherent material from the vessel wall, it is often difficult to remove the material from the vessel itself since the Treratola device does not offer any method to unwind or aspirate the material. As the Treratola device is removed from the vessel, it typically passes through a close-fitting orifice such as an introducer sheath. Any material that is wound around the Treratola device is typically pushed off as it enters the sheath, and such material thus remains in the vessel.
Accordingly, apparatus and methods for removing material from aorto-venous grafts, blood vessels, or other body lumens would be useful.